IACUC / LARC STANDARD PROCEDURES

RODENT SPECT/PET IMAGING
IMAGING PROCEDURES FOR LIVE MICE AND RATS IN A SPECT/CT OR PET/CT SCANNER
(Posted November 2006)

Description of procedure:

1. SPECT or PET Only

Mice or rats will be imaged under general anesthesia. Radionuclide tracers for SPECT or PET imaging will be injected via IP (intraperitoneal) or IV (intravenous) routes. After injection, depending on the specific imaging agent being used, there may be a delay prior to imaging, during which the animal may be allowed to recover from anesthesia. Skilled operators are not required to anesthetize animals for IV or IP injections.

The animal will be anesthetized prior to the actual imaging process, and then maintained under anesthesia during the imaging study. The animal will be positioned within the scanner, and will be visually monitored throughout the scan. The SPECT or PET imaging is performed via the detection of radiation emitted from the tracers that have been injected into the animal.

Following the scan, the animal will be allowed to recover from anesthesia and housed at China Basin for repeated imaging studies if needed. Recovered animals can be maintained for up to 1 year for repeated imaging studies. Each session will last 30-60 minutes. At the end of the imaging studies, the animal will be returned to the investigator if the investigator’s approved IACUC protocol allows such transfer, or euthanized.

2. CT Only

Mice or rats will be imaged under general anesthesia. CT contrast media may be injected via IP (intraperitoneal) or IV (intravenous) routes, or administered orally prior to or during imaging if necessary. After injection, depending on the specific contrast agent being used, there may be a delay prior to imaging, during which the animal may be allowed to recover from anesthesia. Skilled operators are not required to anesthetize animals for IV or IP injections or for oral dosing.

The animal will be anesthetized prior to the actual imaging process, and then maintained under anesthesia during the imaging study. The animal will be positioned within the scanner, and will be visually monitored through the scan. During CT scans, the animal will be imaged using x-rays.

Following the scan, the animal will be allowed to recover from anesthesia and housed at China Basin for repeated imaging studies if needed. Recovered animals can be maintained for up to 1 year for repeated imaging studies. At the end of the imaging studies, the animal will be returned to the investigator if the investigator’s approved IACUC protocol allows such transfer, or euthanized.

3. Combined SPECT and CT, or PET and CT

Mice and rats will be imaged under general anesthesia. The animal will receive radionuclide tracers and/or CT contrast media via IP (intraperitoneal), IV (intravenous), or oral routes. After administration, depending on the imaging agent being used, there may be a delay prior to or during imaging, during which the animal may be allowed to recover from anesthesia.

The animal will be anesthetized prior to the actual imaging process, and then maintained under anesthesia during the imaging study. The animal will be positioned within the scanner, and will be visually monitored through the scan. The SPECT or PET imaging is performed via the detection of radiation emitted from the tracers that have been injected into the animal. During CT scans, the animal will be imaged using x-rays.

Following the scan, the animal will be allowed to recover from anesthesia and housed in the animal facility for repeated imaging studies if needed. Recovered animals can be maintained for up to 1 year for repeated imaging studies. At the end of the imaging studies, the animal will be returned to the investigator if the investigator’s approved IACUC protocol allows such transfer, or euthanized.

4. If you are collaborating with the Radiology department, you must generate a modification to your approved IACUC protocol in RIO . This modification should include the following:

1. An explanation of why you are adding the imaging procedures
2. Addition of the Radiology personnel who will be handling your animals and performing the procedures
3. Addition of the locations (specific rooms) where the procedures will take place and where the animals will be housed
4. Addition of all contrast agents, anesthesia, analgesia, etc. to the “Agents” section in RIO
5. In lieu of describing the procedures listed here, you may reference this document. For example, “imaging procedures will be carried out as described in the “ Imaging Procedures for live mice and rats in a SPECT/CT or PET/CT scanner” Standard Procedure.

   This modification must be reviewed and approved before imaging may begin. Contact the IACUC office 476-2197 with questions.

Regulated materials:

• This procedure generally uses gaseous anesthesia (e.g., isoflurane) which is recommended and is not a regulated material. Alternative anesthetics that are controlled substances (e.g., ketamine, pentobarbital, buprenorphine) require a CSA.
• Radionuclide tracers are regulated materials and require a RUA.
• All agents should be listed in the “Agents” section of the protocol in RIO.

Literature search words required:

Key Words	Search Site	Years Covered
Search 1:small animal and SPECT AND CT Search 2: (mouse OR rat) and dual modality and imaging	Pubmed	1985-2005
Search 1: (small animals AND SPECT AND CT); Search 2: (mouse OR rat) and dual modality AND imaging	Inspec	2000-2005
Search 1: vascular perfusion AND (mouse OR rat). Search 2: tumor growth AND (mouse OR rat). [Review papers only]	Pubmed	2000-2005

Agents:

• Isoflurane, potential injectables depending on protocol.
• This procedure involves anesthesia, and injected contrast media.
• All agents administered to animals should be listed in the “Agents” section of RIO.

Adverse effects, monitoring, and management :

Adverse Effects
Procedure, Agent or Phenotype	Potential Adverse Effects	Management
Contrast Agents	None anticipated, as animals will be anesthetized throughout procedure	None needed
Radiation dose from tracers and CT	Nausea (Manifested as generalized ill appearance) and/or diarrhea	We will image the animal acutely and under anesthesia, and then will euthanize the animal.
Radiation dose from tracers and CT	Susceptibility to infection	We will treat with antibiotics in consult with veterinary staff at LARC for recommendations about management on a case-by-case basis.

Monitoring Parameters
Monitoring Parameters	Frequency	PI/Lab will Document
General appearance and behavior	Daily Monday - Friday	Yes

Describe the conditions, complications, and criteria (e.g. uncontrolled infection, loss of more than 15% body weight, etc.) that would lead to removal of an animal from the study, and describe how this will be accomplished (e.g. stopping treatment, euthanasia).

Animals will be removed from the study following criteria in the protocol from which the animal was originally transferred. In addition, an affected animal will be removed from the study if it exhibits signs such as labored respiration, decreased appetite or activity, poor grooming, distress, uncontrolled infection, uncontrolled edema, or 15% of weight loss. Any such conditions, complications, and instances will be documented. Animals removed from the study will be euthanized.